Petranek Reservoir

TR-ARMELLS CREEK· Fergus, Montana· Built 1937· Earth· 34 ft tall

Key Takeaway

Petranek Reservoir is classified as low hazard in Montana. It was completed in 1937 and is 89 years old. Its primary use is fire protection.

Physical Details

Dam Height 34 ft (taller than 92% in MT)
Dam Length584 ft
Dam TypeEarth
Max Storage125 acre-ft
Normal Storage120 acre-ft
Year Completed1937 (89 years old)
NID IDMT01032

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

DAVID H. & BARBARA PETRENEK

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Petranek Reservoir?

Petranek Reservoir is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Petranek Reservoir?

Petranek Reservoir is owned by DAVID H. & BARBARA PETRENEK (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Petranek Reservoir built?

Petranek Reservoir was completed in 1937, making it 89 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Petranek Reservoir?

Petranek Reservoir serves the following purposes: Fire Protection, Stock, Or Small Fish Pond. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Petranek Reservoir?

Petranek Reservoir has a dam height of 34 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.